Encoders are used to measure angular or linear motion. A common use of encoders is for computer numeric control (CNC) machines. Encoder housings may be made of metal, e.g., in a bearing encoder, or plastic, e.g., in a modular encoder, and may include printed circuit boards (PCB).
In modular encoders, the surface of the housing that contacts the motor is made of non-conductive plastic. In some situations, an O-bracket and a wire may be soldered to the PCB to create an electrical connection between the PCB and the motor.
U.S. Pat. No. 4,338,517 to Perrine is believed to relate to a shaft rotation sensor. A modular incremental rotary shaft encoder is preassembled within its housing and then installed and aligned upon the shaft of which rotation is to be sensed. The encoder housing loosely confines a thin disc assembly having a shaft receiving aperture dimensioned to be a press fit upon the shaft. The encoder is installed simply by pressing the housing and the disc assembly therein upon the shaft and fixing the housing to the shaft support. The disc assembly plane of rotation and the disc to detector gap are fixed by inserting a slender elongated installation tool through the housing cover into engagement with the disc assembly and pressing and bending the disc assembly against a fixed stop while the shaft and disc assembly are rotated. A pointed tool is inserted through the housing against the disc assembly to hold the latter against rotation while the shaft is carefully rotated to provide for rotational indexing of the disc assembly.
U.S. Pat. No. 5,859,425 to Mleinek et al. is believed to relate to an encoder having first and second housing portions and guide means. The encoder includes a casing having an open end and a base which fits in the open end. Trapezoidal cutouts in the casing are arranged to receive partly trapezoidal projections on the base. The casing contains an optical sensor, a circuit board for operation of the sensor, and a timing disc mounted on a rotary hub. The hub has a passage for a drive shaft of a motor, and the passage is in register with an opening in the base. During assembly, the drive shaft is passed through the opening in the base and the motor and casing are urged towards one another to push the base into the casing. When the base enters the casing, the projections are received in the cutouts and a guide surface in the casing engages a centering surface on the hub. Once the projections are in the cutouts, the casing and the base are rotated relative to each other to secure the base to the casing. Due to the trapezoidal shape of the cutouts and the partly trapezoidal shape of the projections, the casing moves in a direction away from the base during rotation. This causes the guide surface of the casing to disengage from the centering surface of the hub.
There is believed to be a need for a mounting arrangement for an encoder that may reduce tooling costs, that may reduce part costs, that may simplify inventory management, that may be easy to use and may be adaptable to different situations.